edit.rs

use rayon::prelude::*;
use std::io::BufRead;

fn edit_distance(s1: &str, s2: &str) -> usize {
    if s1.len() > s2.len() {
        return edit_distance(s2, s1);
    }

    let mut distances: Vec<usize> = (0..=s1.len()).collect();
    for (i2, c2) in s2.chars().enumerate() {
        let mut distances_ = vec![i2 + 1];
        for (i1, c1) in s1.chars().enumerate() {
            if c1 == c2 {
                distances_.push(distances[i1]);
            } else {
                distances_.push(
                    1 + distances[i1]
                        .min(distances[i1 + 1])
                        .min(distances_[distances_.len() - 1]),
                );
            }
        }
        distances = distances_;
    }
    distances[distances.len() - 1]
}

fn main() {
    let mut argv = std::env::args();
    argv.next();
    let needed_distance: usize = argv.next().unwrap().parse().unwrap();
    let clues: Vec<String> = argv.collect();

    let dict: Vec<String> = std::io::stdin()
        .lock()
        .lines()
        .flat_map(|word| word.into_iter())
        .map(|word| word.trim().to_lowercase())
        .collect();

    for word in dict
        .into_par_iter()
        .filter(|word| {
            clues
                .iter()
                .all(|clue| edit_distance(clue, &word) == needed_distance)
        })
        .collect::<Vec<String>>()
        .into_iter()
    {
        println!("Found a word! {}", word);
    }
}